Process of treating wood.



.the art to which it pertains HARRY W. BBOADY,'0F BAYSIDE, NEW YORK.

PROCESS or TREATING WOOD.

No Drawing.

To all whom it may concern:

Be it known that I, HARRY IV. BROADY, a citizen of the United States,and a resident of Bayside, in the county of Queens, State of New York,have invented certain new and useful Improvements in Processes ofTreating food, of which the following is a description in such full,clear, and exact terms as will enable any person skilled in to make anduse the same.

My invention relates to a process of preserving wood by treating it witha waxy compound which lines or covers the cell walls and cavitiesthereof.

Heretofore such treatment has been attempted by simply submerging thewood in the heated compound. But this has resulted in incomplete successbecause the compound thus applied has filled and agglomerated in thecavities at some places and to other places in the wood the compound hasnot reached at all. The object of my present invention is to overcomethese defects and to cause the compound uniformly to enter to the remoterecesses of the wood and simply line or coat the walls of such recessesinstead of gathering in masses which clog .and fill the same.

Any desired wax-like impervious or waterproof material or compound ofmaterials which will spread out in' a film on the surfaces treated andwhich may be softened or rendered fluid by heat may be employed, thoughI prefer a compound of approximately 25% bitumen and 75% paraflin.

The ingredients of the wax-like, impervi ous mixture are mixed bymelting them together. The temperatTIre required, in the case of bitumenand paraffin is approximately 160 F. to 180 F. 7

When the hot bath is thus prepared the wood in its normal green state,or if desired in cured or partly cured form, is submerged in the mixtureand the temperature raised to approximately 212 to 265. (Thesetemperatures are deemed best for waterproofing composed of bitumen andparaffin but may be varied if desired or when other materials are used).The result of this submersion of the wood is that the moisture thereinis driven off as steam and escapes in bubbles through the bath duringand after which the mixture enters the pores and cavities of the wood.The mixture should be fluid so that it readily penetrates the wooddeeply.

Specification of Letters Patent.

Application filed April 14, 1916.

Patented Feb. 2'7, 1917.

Serial No. 91,109.

It is an object of my invention to cause the mixture to spread out in afilm or coat along the inner surfaces of the walls of the cavities andnot simply to clog or plug up and completely fill these cavities.

I attain this condition by treating the wood to a primary submersionwhich is preferably carried on until the bubbling ceases, this bubblingbeing due to the escape of moisture (steam) and gases from the wood. Thetime required for the primary submersion depends upon the size and kindof wood treated. It drives off part of the moisture and part of theexpanded gases from the wood and effects penetration as complete as maybe at that time. is now allowed to cool, preferably with the Woodtherein. The cooling of the bath produces an internal vacuous condition;the internal cavities are filled to a greater or less extent with theliquid which hardens in the wood; after which the bath is again heatedand liquefied as before. The second heating should drive out the excessdeposited in the vessels and cavities. There is practically no bubbling.on the second heating.

The treatment therefore provides a more uniform coating for the cavitiesin the wood. In this way I secure the principal object of my invention,2'. e. the uniform coating of the internal cavities and the thoroughpenetration of the wood. If desired the wood may be withdrawn from themixture after the first heating and the second heating of p the woodcarried on in any suitable chamber.

It is my opinion, based on my experiments, that this deep, uniformcoating of the wood cavities upon heating, cooling and reheating of themixture is due largely to the action of the gases in the poresexpanding, contracting and condensing under the varying heat degrees.The gases expand under the first treatment and that part not actuallyvented or driven off at the first heating contracts or condenses oncoolmg The bath double heating in the bath described it is withdrawnWhile the bath is yet hot, the excess of the composite material isallowed to drain ofl? and that remaining in the wood to cool and hardento form the permanent treatment of the'wood.

What I claim is 1. The process of treating wood to coat or line its cellwalls or cavities, which consists in treating it to penetration by andin a bath of wax-like material heated to fluidity, cooling said bathwith the wood therein, heating the wood and the material therein tofluidity of the latter and cooling the wood and said material therein.

2. The process of treating wood to coat orline its cell walls orcavities, which consists in treating it to penetration by and in a bathof wax-like material heated to fluidity, cooling the wood and thematerial deposited threin, reheating the wood and the material thereinto fluidity of the material and again cooling the Wood and said materialtherein.

In testimony whereof I have hereunto signed my name in the v presence oftwo witnesses.

HARRY W. BROADY. Witnesses:

ISAAC B. OwENs, PATRICK A. BoLeER.

